Key-lever-lock for key-lever type machines



NOV. 16, 1937. v TAPP 2,099,147

KEY LEVER LOCK FOR KEY LEVER TYPE MACHINES Filed Feb. 4, 1937 Jn Vi IY/tZl/EZTOR. BY 71%,

A TTORNEY Patented Nov. 16, 1937 UNITED STATES PATENT OFFICE KEY-LEVER-LOCK FOR KEY-LEVER TYPE MACHINES Application February 4, 1937, Serial No. 124,020

2 Claims.

The objects of my invention are, first, to lock the key-levers of key-lever type machines with certainty at any desired position; second, to provide flexibility enough to permit the last letter struck at the right end of a line to have a full space; and, third, to prevent the piling of letters at the right end of a line. due to imperfect and inefiicient key-lever-lock control.

I attain these objects by mechanism illustrated in the accompanying drawing, in which- Figure 1 is a front elevation of part of a key-lever typewriter showing the relation of my key-lever-lock to said typewriter. In order to show this relation, the front of the typewriter frame and the space-bar have been removed to disclose how my invention is connected to the side frames of said typewriter, and how it is related to the key-levers projecting through the key-lever-comb. No new connecting parts for line-lock-bar and typewriter are required, the present connectionsserving perfectly in the typewriter shown.

Figure 2 shows a standard line-lock-bar, with my alignment-bar connected thereto; said linelock-bar provided with control-crank connected with line-lock-connecting-link.

Figure 3 shows a standard line-lock-bar, my alignment-bar connected thereto, my movable segments (separated by segment-rings) connected to said line-lock-bar, springs connected to my alignment-bar, and the relations of my movable segments and their control springs to each other and to said line-lock-bar and alignment-bar.

Figure 4 is a side view of a key-lever surmounted with its cup, a tooth of the comb, and an end view of one of my segments, showing the relative positions and relations of the keylever, comb and segment. The solid line shows position of segment at rest, the dotted line shows position of segment when locking key-levers.

Figure 5 consists of two parts: The left, a linelock-bar, a segment in position thereon, and tongue of segment projecting under alignmentbar; the right, a view of segment partly engaged on line-lock-bar, and segment ring.

Similar numerals refer to similar parts throughout the several views.

My invention embodies an essential mechanical difference from line-locks devised to lock whole key-boards by one rigid mechanism in one operation at a given instant: such line-locks attempt to control all key-levers at a given moment, whereas my key-lever-lock for key-lever type machines exerts locking control by sections or banks, and, by so doing, achieves a necessary flexibility. With present rigid line-locks, when a margin-stop strikes a line-lock-lever, if, at that instant, any key-lever is depressed, said line-lock-lever cannot move to allow the carriage to give the last key-lever struck full writing space at right end of line. The result is the crowding of the last letter struck against the second-last letter struck. This action occurs because the present line-lock-assembly and the line-lock-lever have no flexibility or adjustment in operation.

With my key-lever-lock for key-lever type machines, if a key is struck at the instant the margin-stop strikes the line-lock-lever, said linelock-lever can nevertheless move a little, just enough to allow normal full space to print the last letter. This result is only possible with, and is only obtained because of, a small movability achieved by locking the key-levers in blocks or banks with movable segments, instead of looking them as a whole.

With my invention, when a margin-stop strikes a line-lock-lever, the present standard mechanism forces a line-lock-connecting-link, joined at front end with a control-crank attached to a line-lock-bar, backward from front of typewriter. This action rotates said line-lock-bar inward. As my alignment-bar is rigidly attached to said line-lock-bar by means of screws inserted through the bushings of said alignment-bar, said rotation lifts said alignment-bar and forces my segments below underside key-lever projections. Until released in a usual manner, my segments continue to be held in this position by the tension control of coiled springs upon the tongues of my segments.

Beginning at the left end of my key-lever-lock for key-lever type machines, segment number 1 controls key-levers numbers 1, 2, 3, 4; segment number 2 key-levers numbers 5, 6, '7, 8; segment number 3 key-levers numbers 9, 10, 11, 12; segment number 4 key-levers numbers 13, 14, 15, 16; segment number 5 key-levers numbers 17, 18, 19, 20; segment number 6 key-levers numbers 21, 22, 23, 24; segment number '7 key-levers numbers 25, 26, 27, 28; segment number 8 key-levers numbers 29, 30, 31, 32; segment number 9 keylevers numbers 33, 34, 35, 36; segment number key-levers numbers 37, 38, 39, 40; segment number 11 key-levers numbers 41, 42, and spacebar-lever.

My invention is applicable to any machine which uses key-lever type control. In the operation of typewriting, key-levers are continually desame instant, and, if any key-lever is depressed,

in the act of typewriting at the moment of looking, the result is the piling of two or more letters in one space at the right end of the line being written; because, if any key-lever is depressed at the moment the carriage stops, a letter will nevertheless print. If a second key-lever is depressed before a first-depressed key-lever comes to rest, a second letter will also print and this can continue until all key-levers have come to rest. With rigid integral line-lock assemblies, so long as one key-lever is depressed, another key-lever. can be depressed also.

" My=-invention overcomes the foregoing defects by control of the movements of key-levers by a series of movable segments rotating upon a linelock-bar. Ten segments lock blocksor banks of four key-levers. The eleventh segment locks two key-levers and one space-bar-lever. There are eleven segments. Each segment is provided with a tongue, which segment-tongue projects to and across the underside of the alignment-bar, the outer half of said tongue being bent or deflected downward'so as to engage and retain the coiled springs attached to the underside of said alignment-bar. The segments themselves engage the line-1ockbar by means of projections near each end, which projections are curved to form hollow circles or rings, the upper ends thereof being soldered or brazed to the flat outer surface of the segment. These rings permit the segments to rotate on the line-lock-bar. Their rotary motion ishowever very short and they are controlled and returned toloriginal position by elevensmall coiled springs set below the eleven segmenttongues These coiled springs are attached to the alignment-bar, their twenty-two ends being inserted through twelve small holes bored in the narrow flange which forms the lower side and inner edge of said alignment-bar, said ends being bent over the edge of the flange for retention. The inner surface of said alignment-bar is a right angle extending full length, the outer surface is convex, terminating at each end in integral projections or lugs which include the bushings through which the line-lock-bar is inserted. Between each segment is a thin segment-ring which separates the segments slightly, permits easy operation, and prevents jamming and interfer-. ence.

In operation. at the instant 'a margin-stop strikes a line-lock-lever and locks the key-levers, if one key-lever is depressed at such instant, no other key-lever on the key-board can be depressed at the same time, as only the segment controlling the depressed key-lever remains unlocked, the remaining ten segments have locked the remainder of the key-board, and the segment controlling the depressed key-lever also looks its block or bank of key-levers an instant before said depressed key-lever comes to rest, thus locking the entire key-board. To illustrate:

If the letter a is being depressed, and the margin is set to stop when said letter a is printed, the segment controlling the block or bank of key-levers containing letter a will remain unlocked until said letter a is printed in a full letter-space; but the remaining ten segments will have already locked their respective blocks or banks of key-levers. When the letter a is printed and its key-lever is released, the segment which controls said key-lever will also lock instantly, and the entire key-board will now be'locked. It is impossible with the touch system of typewriting, now universally employed, to strike two key-levers, located in any one block or bankcontrolled by any one of my segments, fast enough to prevent any one of my segments from looking such block or bank of key-levers. My invention locks key-levers in banks or blocks to correspond with thetouch system of typing, and each bank of key-levers operated by any finger is locked by an individual segment.

My key-lever-lock for key-lever type machines can be installed in place of the line-lock now used in one wellI-known typewriter, without any change whatever; and, my invention can be adapted to any other key-lever typewriting machine by suitinstance changing the nature, essential mechanical construction, or operation of my invention.

As to durability, my invention is so constructed that it will last at least as long as any key-lever type machine can last.

For sake of convenient reference, I set all numerals referring to the drawing in this paragraph only. In Figure 1, 50 indicates side frames of typewriter; 5| my key-lever-lock; 59 key-1 levers, and 60 key-lever-comb. In Figure 2,. 52 indicates line-lock-bar; 53 alignment-bar con nected therewith. In Figure 3, 52 indicates linelock-bar, 53 alignment-bar, 54 segments one to eleven inclusive; 55 springs connected to alignment-bar; 56 lugs with bushings, 5'! segmentrings,-and 58 segment-tongues. In Figure 4, 59 indicates key-lever; 60 tooth of comb; and BI end view of segment, the solid line showing position at rest, the dotted line showing position,

when looking key-levers. In Figure 5, 52 indi cates line-lock-bar, 53 alignment-bar, 54 segments, 51a segment-ring, and 58 a segmenttongue; Because the control-crank, line-lockconneoting-link, and key-lever projection are standard parts, and in nowise parts of my invention, but;necessarily shown to indicate the relations of my invention thereto, I indicate controlcrank by a, and line-cock-connecting-link by b in Figure 2; and key-lever projection by c", in Figure 4.

It is the aim of the-makers of, and the desire of the users of key-lever type machines, that such machines be as nearly precision-perfect as possible. The defects which my invention now overcomes have always been practical operative disadvantages. It is now quite conceivable, with my invention as model and base for ideas and experiments, that mechanical changes can be incorporated to the extent of locking each keylever with a separate segment, and other material modifications can also be made, for mere mechanical ingenuity is an obvious outgrowth of inventivecreation. Therefore I do not limit myself to the particular construction shown and described in this drawing and-specification, but broadly claim all rights inherent in my original discovery and efficient meansto accomplish reto which my rality of segments rotatably mounted on said line-lock-bar and provided with tongues projecting to and under said alignment-bar, and a plurality of coiled springs attached to and below said alignment-bar to control and restore position to said segments by means of said segmenttongues.

2. In combination with key-lever type machines, a key-lever-lock, consisting of a line-lock- 10 bar, an alignment-bar secured thereto and 0scillating with said line-lock-bar, a plurality of segments adapted to rotate upon said line-lockbar, said segments separated by segment-rings mounted on said line-lock-bar, each segment equipped with a tongue projecting to and under said alignment-bar, each segment-tongue engaged with and controlled and returned to position by a coiled spring attached to the underside of said alignment-bar.

LORA EVANS TAPP. 

